The present invention is drawn to a process for the production of high quality petroleum tar pitch for use as a binder in the manufacture of electrodes for the aluminum, and steel industries.
High quality petroleum tar pitch can be used in a variety of applications. One of the most important uses for high quality petroleum tar pitch is in the manufacture of anodes made from calcined petroleum coke and a binder pitch. The anodes are used in the production of primary aluminum. Presently anodes for use by the aluminum and steel industries are manufactured employing almost exclusively coal tar pitch as the binder. Coal tar pitch is a by-product of the carbonization process of mineral coal. Commercial specifications for binder pitch used in the production of electrodes are as follows:
______________________________________ HIGH S.P. LOW S.P. PITCH PITCH ______________________________________ Conradson Carbon, (wt. %) 56 40 Density @ 15.degree. C., (gr/cc) 1.32 1.25 Mettler Softening Point, .degree.C. 110-115 55-63 Quinoline Insolubles, (wt. %) 13-18 10-15 ______________________________________
There have been many attempts in the past to produce petroleum tar pitch suitable for use as a binder in the manufacture of electrodes. These known processes are disclosed in U.S. Pat. Nos. 3,725,240, 4,039,423 and 4,243,513. None of the foregoing processes have been able to produce commercial petroleum tar pitch suitable for use as a binder in the manufacture of electrode for the aluminum and steel industries. Naturally, it is highly desirable to provide a process for the production of high quality tar pitch which would allow for the economic production of pitch suitable for the manufacture of electrodes.
Accordingly, it is a principal object of the present invention to provide a process for the production of petroleum tar pitch.
It is a particular object of the present invention to provide a process as set forth above wherein the quality of the petroleum pitch is suitable for use as a binder in the manufacture of electrodes.
It is a still further object of the present invention to provide a process as set forth above employing as a feed a hydrocarbon feedstock characterized by high levels of aromatics.
It is a still further object of the present invention to provide a process as set forth above which would allow for the economic production of petroleum tar pitch.
Further object and advantages of the present invention will appear hereinbelow.